1. Field of the Invention
The present invention relates to a structure for mounting a seat in a body of a vehicle.
2. Description of the Related Art
An automobile, which is a representative example of vehicle, generally has two front seats (driver seat and passenger seat), and optionally a rear bench seat. FIG. 6 is a side view of a main part of a conventional structure for mounting an automobile seat, with a front seat mounted thereon. FIG. 7 is an enlarged perspective view of a main part of a conventional structure for mounting a front seat, showing an arrangement of a cross member and a seat-mounting bracket.
As shown in FIG. 6, in a conventional structure for mounting an automobile seat, a front seat 100 to be used as a driver seat or a passenger seat has base frames 120 provided on a lower face of a seat cushion 110 in such a manner that the base frames 120 (and thus the front seat 100) can slide in a front-rear direction along a seat rail 300 bridging a cross member 200 and a seat-mounting bracket 400. The seat rail 300 is fixed to a floor panel 800, by fixing a front end portion and a rear end portion of the seat rail 300 to the cross member 200 and the seat-mounting bracket 400 provided on the floor panel 800, respectively (see, for example, Japanese Patent Application Kokai No. 2001-63620A, paragraphs 0012-0016 and FIGS. 3 and 5).
As shown in FIG. 7, the cross member 200 extends in a width direction of the car body between a pair of side sills 600 each extending in a front-rear direction on both lateral sides of the car body, and bridges the pair of side sills 600 and a center sill 500 extending in a front-rear direction at a center of the car body (only one side sill is shown in the drawing).
The center sill 500 is located at a center of the car body in nearly parallel with the side sills 600.
The seat-mounting bracket 400 is fixed to the center sill 500-side lateral face of the side sill 600 by spot welding.
The floor panel 800 is spot-welded to the lower faces of the side sill 600, the cross member 200 and the seat-mounting bracket 400, and supported by the center sill 500 placed below the floor panel 800.
When an automobile having the above-described structure crashes head-on, an inertia force in a forward direction of an arrow G is exerted on the front seat 100, as shown in FIG. 6. As a result, a load in a direction of an arrow H is exerted on the seat-mounting bracket 400, which tends to detach the seat-mounting bracket 400 from the floor panel 800. Therefore, conventionally, a reinforcing bracket 700 for strengthening the seat-mounting bracket 400 is provided and the seat-mounting bracket 400 is fixed to the floor panel 800 with a bolt 900 (see FIG. 7), in order to prevent the seat-mounting bracket 400 from being detached from the floor panel 800 during collision.
The reinforcing bracket 700 is placed immediately below the seat-mounting bracket 400 through the floor panel 800, with one end of the reinforcing bracket 700 being fixed to the side sill 600 and the other end fixed to the center sill 500. In other words, the reinforcing bracket 700 bridges the side sill 600 and the center sill 500 while supporting the seat-mounting bracket 400.
However, in the case of the structure disclosed in the above-mentioned patent document, problems arise in that addition of the reinforcing bracket 700 and the bolt 900 to the seat-mounting bracket 400 inevitably increases the number of parts, assembling processes and weight of the car body.
Therefore, it would be desirable if a structure for mounting a vehicle seat is provided that can securely mount a seat in a vehicle body, without increasing the number of parts, assembling processes, weight of the vehicle body and the like.